Open AccessSpatiotemporal variations in vertical gravity gradients at the Campi Flegrei caldera (Italy): a case for source multiplicity during unrest?
Author(s) -
Gottsmann Joachim,
Camacho Antonio G.,
Tiampo Kristy F.,
Fernández José
Publication year - 2006
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.2006.03157.x
Subject(s) - caldera , geology , unrest , tiltmeter , seismology , volcano , subsidence , geodesy , inversion (geology) , geophysics , tectonics , geomorphology , structural basin , amplitude , physics , quantum mechanics , politics , political science , law
SUMMARY We present an evaluation of residual vertical gravity–height change gradients obtained from gravimetric and elevation data between 1982 and 2000 at the Campi Flegrei caldera (CFc) in Italy. Spatial and temporal variations in the gradients are indicative of multiple causative sources during unrest, in particular for ground subsidence from 1988 onwards. Supported by results obtained from time‐series inversion for the period 1988–2000 using a random search approach of a purely elastic earth model and a genetic algorithm accounting for elastic‐gravitational effects, we propose a centre of dilatation undergoing predominantly pressure changes yet negligible mass changes as the dominant cause for caldera deflation. Mass fluctuations in randomly active secondary sources along the periphery of the CFc can be best explained by dynamic changes along the caldera boundary (ring) faults.